Browse Topic: Aircraft propulsion systems

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Aircraft and Aircraft Engine Fuel Pump Low Lubricity Fluid Endurance TestARP1797B (Current)11/26/2025
This procedure is intended to apply to fuel pumps. This procedure will be defined in terms of recommended test fluid, test setup, test conditions, and test method. This procedure may be used for other fuel system components, by testing in conjunction with the pump, which normally supplies the component inlet flow, or a substitute test pump of similar capacity. This procedure may be used, with variations in test conditions and test fluid for performing pump evaluation tests. Tests at progressively increasing pump speeds and pressures will provide design limitation data. Alternate test periods on a test pump and another pump, of a design for which actual service durability is known, will provide useful comparison data.
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
On-Board Fuel Sensing for UAS and Ground Vehicle Applications2024-01-41289/16/2024
Abstract The variability in fuel, particularly for fuel blends containing sustainable aviation fuels (SAFs), emphasizes the importance of understanding fuel properties for optimizing engine performance. This paper introduces spectroscopic fuel sensors capable of real-time estimation of jet fuel properties, mainly derived cetane number (DCN). While initially developed for unmanned aircraft systems (UAS), the paper explores their potential in ground vehicle applications: enhancing engine performance through sensing for feed-forward control and fuel property monitoring at fuel depots. The fuel sensing technologies are based on spectroscopic techniques coupled with machine learning (ML) approaches. The combination of these techniques demonstrates a promising solution for a wide spectrum of fuel applications.
Patel, Dev B., Sutar, Ashish, Abraham, Abhinav, Ambre, Dhananjay, Brezinsky, Kenneth, Lynch, Patrick T., Okada, Haruna, Stafford, Jacob M., Miganakallu, Niranjan, Sanders, Scott, Rothamer, David, Mayhew, Eric, Kim, Kenneth S.
Dynamic Load Analysis of an eVTOL Aircraft Propulsion SystemF-0079-2023-180565/16/2023
Wang, Dexin, Peeples, Jennifer, Valente, Geirgui, Johnston, Andrew, Riache, Younes, Mahmoud, Hanafy
RM13006 - Process Control MethodsAESQRM0062021099/7/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13003 - Measurement Systems AnalysisAESQRM0032021055/17/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
Gas Turbine Engine Performance Presentation for Computer Programs Using FortranAS4191A (Current)5/13/2021
This SAE Aerospace Standard (AS) provides a method for gas turbine engine performance computer programs to be written using Fortran COMMON blocks. If a “function-call application program interface” (API) is to be used, then ARP4868 and ARP5571 are recommended as alternatives to that described in this document. When it is agreed between the program user and supplier that a particular program shall be supplied in Fortran, this document shall be used in conjunction with AS681 for steady-state and transient programs. This document also describes how to take advantage of the Fortran CHARACTER storage to extend the information interface between the calling program and the engine subroutine.
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
RM13004 - Defect Prevention Quality Tools to Support APQP & PPAPAESQRM0042021033/25/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13145 - Advanced Product Quality Planning (APQP) and Production Part Approval Process (PPAP) within AerospaceAESQRM1452021033/15/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13011 - Rework and Production Repair of Non-Conforming ProductsAESQRM0112021033/15/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13102 - First Article InspectionAESQRM1022021033/15/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13002 - Alternate Inspection Frequency PlansAESQRM0022021033/8/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13000 - 8D Problem Solving MethodAESQRM0002021033/8/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
RM13006 - Process Control MethodsAESQRM0062021033/8/2021
AS13100 AESQ Quality Management System Requirements for Aero Engine Design and Production Organizations Standard was created to replace customer specific quality requirements – leading to simplification and harmonization between engine manufacturer supply chains. AS13100 is supported by a series of 13 AESQ Reference Manuals (RM) that provide additional detail on certain subjects to describe the intent of the standard and to provide guidance on deployment. The Reference Manuals are designed to enable the supply chain to deploy the AS13100 requirements efficiently and effectively. The AESQ RMs provide case studies, guidance material, forms and checklists specific to each section of the standard to aid the user with implementation.
Aerospace Engine Supplier Quality Strategy Group
Lubricating Oil, Aircraft Piston Engine (Ashless Dispersant)J1899_202010 (Current)10/28/2020
This SAE Standard establishes the requirements for lubricating oils containing ashless dispersant additives to be used in four-stroke cycle, reciprocating piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-22851. Users should consult their airframe or engine manufacturers manuals for the latest listing of acceptable lubricants.
E-38 Aviation Piston Engine Fuels and Lubricants
Lubricating Oils, Aircraft Piston Engine (Non-Dispersant Mineral Oil)J1966_202010 (Current)10/28/2020
This SAE Standard establishes the requirements for nondispersant, mineral lubricating oils to be used in four-stroke cycle piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-6082. Users should consult their airframe or engine manufacturers manuals for the latest listing of acceptable lubricants.
E-38 Aviation Piston Engine Fuels and Lubricants
Measurement of the Total Ash Content of Aviation Piston Engine Oils by a Calculation MethodJ1787_202009 (Current)9/29/2020
This SAE Recommended Practice describes an empirical method for determining the theoretical ash content of aviation piston engine lubricating oils by calculating the equivalent weight of metallic oxides formed at 775 °C based on the metallic elemental concentration. The calculation method of ash determination may be used as an alternate to ASTM D 482 for application to the standards for aviation piston engine lubricating oils.
E-38 Aviation Piston Engine Fuels and Lubricants
Preignition Rating of Spark PlugsJ549_202006 (Current)6/15/2020
This SAE Recommended Practice describes the equipment and procedures used in obtaining preignition ratings of spark plugs.
Ignition Standards Committee
Elastomer: Methyl Phenyl Vinyl Silicone (PVMQ) Very Low Temperature/Aircraft Piston Engine Oil Resistant High Strength/Tear Resistant 45 to 55 Durometer Type ‘A’ Hardness For Products in Aircraft Piston Engine Oil/Low Temperature EnvironmentsAMS3345G (Current)5/18/2020
This specification covers a methyl phenyl vinyl silicone rubber material that can be used to manufacture product in the form of sheet, strip, tubing, molded shapes, and extrusions. For molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications, use the corresponding AMS7000 series specification.
AMS CE Elastomers Committee
Temperature Measurement, Well Insert TypeARP175A (Current)4/14/2020
A-4 Aircraft Instruments Committee
Experimental Analysis of a Multiple Radiator Cooling System with Computer Controlled Flow Rates2020-01-09444/14/2020
The automotive cooling system configuration has remained fixed for many decades with a large radiator plus fan, coolant pump, and bypass valve. To reduce cooling system power consumption, the introduction of multiple computer-controlled heat exchangers may offer some benefits. A paradigm shift from a single large radiator, sized for maximum load, to n-small radiators with individual flow control valves should allow fine tuning of the heat rejection needs to minimize power. In this project, a series of experimental scenarios featuring two identical parallel radiators have been studied for low thermal load engine cooling (e.g., idling) in ground transportation applications. For high thermal load scenarios using two radiators, the fans required between 1120 - 3600 W to maintain the system about the coolant reference temperature of 85oC. In contrast at reduced thermal loads, a single radiator configuration with half the heat transfer surface area required between 550 - 1000 W for the same operating conditions. A 51% reduction in fan and pump power consumption at a lower thermal load, while maintaining coolant temperature about the setpoint value, offers possibilities on redesigning the thermal management system. Given that vehicles often operate at reduced thermal loads, these findings can help improve the overall powertrain performance.
Syed, Zaker, Wagner, John
Influence of Port Water Injection on the Combustion Characteristics and Exhaust Emissions in a Spark-Ignition Direct-Injection Engine2020-01-02944/14/2020
It is well known that engine downsizing is still the main energy-saving technology for spark-ignition direct-injection (SIDI) engine. However, with the continuous increase of the boosting ratio, the gasoline engine is often accompanied by the occurrence of knocking, which has the drawback to run the engine at retarded combustion phasing. Besides, in order to protect the turbine blades from being sintered by high exhaust temperature, the strategies of fuel enrichment are often taken to reduce the combustion temperature, which ultimately leads to a high level of particulate number emission. Therefore, to address the issues discussed above, the port water injection (PWI) techniques on a 1.2-L turbocharged, three-cylinder, SIDI engine were investigated. Measurements indicate that the optimization of spark timing has a significant impact on its performance. The two factors of the water substance itself and spark advance caused by the knock mitigation are trade-offs, which eventually affect the combustion performance. Under knock limited spark advance (KLSA) condition, we find that the application of port water injection could effectively advance the combustion phasing and reduce exhaust gas temperature, which makes it possible to eliminate fuel enrichment and further enhances the fuel economy improvement at the maximum power point. As a result, about 5.2%-18.4% improvements in the fuel economy are obtained under different engine operating conditions. For the exhaust emissions, due to the increasing heat capacity of the mixture and the elimination of fuel enrichment, port water injection techniques cause an 85.3% reduction in particle number concentration. However, it shows that for a given λ, an increase in the water/fuel ratio would cause higher THC emissions, which is contributed to the occurrence of more quenching caused by higher peak combustion pressure. Finally, the potential of PWI on the engine combustion characteristics and emissions performance was revealed.
Fan, Yadong, Wu, Tianbao, Li, Xuesong, Xu, Min, Hung, David
Numerical Investigation of the Effects of Port Water Injection Timing on Performance and Emissions in a Gasoline Direct Injection Engine2020-01-02874/14/2020
Port water injection is considered as a promising strategy to further improve the combustion performance of internal combustion engines for its benefit in knock resistance by reducing the cylinder temperature. A thorough investigation of the port water injection technique is required to fully understand its effects on the engine combustion process. This study explores the potential of the port water injection technique in improving the performance of a turbo charged Gasoline Direct Injection engine. A 3D computational fluid dynamics model is applied to simulate the in-cylinder mixing and combustion for this engine both with and without water injection. Different water injection timings are investigated and it is found that the injection timing greatly effects the mass of water which enters the combustion chamber, both in liquid and vapor form. Comparison have been given between the original engine and the water injection one and the results show that the water injection can reduce the cylinder temperature both in the compressing and combustion strokes. The pressure oscillation is also suppressed which indicates a better knocking resistance for water injection strategy. An optimized injection timings could be found for a particular load condition and also lead to a better combustion performance and emissions.
Yin, Peng, Li, Xuesong, Hung, David, Fan, Yadong, Xu, Min
The impacts of Diesel cycle engines on the operating costs of the Cessna 172 Skyhawk and JT-A aircraft.2019-36-03211/13/2020
Diesel engines have been used on the aeronautical market for a long time. Despite this fact, there are few studies showing the potential cost savings of using this type of technology. In this way, the goal of this paper is to find out whether or not it is advantageous to use an Otto or Diesel cycle engine on general aviation light aircraft. It is well known that both of them have pros and cons, however, the possibility of using Jet A-1 (kerosene) as fuel gives the Diesel engine a clear advantage in a market like Brazil, where the price of the regular piston fuel (AvGas) keeps rising to astonishing values. Throughout this paper, a detailed study of the fixed and variable costs of two similar aircraft, both Cessnas 172 equipped with Otto and Diesel cycle engines is conducted, comparing fuel consumption, performance levels, and other factors. Even though the latter engine has a higher fixed operating cost, the advantages found in this study makes the Diesel motor a step forward of its competitor, whether concerning the flight hour cost or performance.
Diniz, Samuel Cunha, Henrique de Assis Coelho, Eduardo, Rodrigues de Oliveira, Gabriel, de Cardoso Oliveira, Lucas, Morais, Samuel Renan Costa, Vasques, Victor Britto, Jorge Machado, Luiz Henrique
Using Engine Test Data to Model Engine PerformanceAIR5509A (Current)11/5/2019
This document defines the process steps involved in collecting and processing engine test data for use in understanding engine behavior. It describes the use of an aero-thermal cycle model for reduction and analysis of those data. The analysis process may include the calculation of modifiers to match the model to measured data and prediction of engine performance based on that analysis.
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
Aircraft Engine Icing Event Avoidance and MitigationTBMG-347387/1/2019
Innovators at NASA’s Glenn Research Center have developed a new means of avoiding and mitigating icing events for aircraft flying above 14,000 feet, dramatically improving aviation safety and reducing operating costs.
SAE 17.6 Cubic Inch Spark Plug Rating EngineJ2203_201906 (Current)6/11/2019
This SAE Standard defines the standard engine to be used in determining spark plug preignition ratings. The engine is known as the SAE 17.6 Cubic Inch Spark Plug Rating Engine.
Ignition Standards Committee
Diagnostic Features from Aircraft Propulsion Bearings in Accelerated Aging ExperimentsF-0075-2019-146145/13/2019
Over the course of a long-duration aging of helicopter drivetrain bearings to examine the consumption of grease life, both vibration and acoustic emission sensing was used to monitor the bearing response as the grease life was consumed through this aging. Acoustic emission is evaluated against vibration in terms of signal trends over the course of the experiment. Common signal metrics are calculated to yield condition indicators, and machine learning techniques are applied to the vibration and acoustic emission data. For the 862 hour duration test run equivalent to over 6700 hours on wing, features of these signals trend with increased degree of aging. Autoencoders were used to enrich existing set of traditional condition indicators and principle component analysis was effectively used for feature fusion. This measured trending shows promise for future onboard Health and Usage Monitoring Systems which may adopt new sensing and data analysis modalities to trend the condition of mechanical systems.
Dykas, Brian, Nenadic, Nenad, Hood, Adrian, Zhu, Edward
High Power-Density, High Efficiency, Mechanically Assisted, Turbocharged Direct-Injection Jet-Ignition Engines for Unmanned Aerial Vehicles01-12-01-00025/2/2019
More than a decade ago, we proposed combined use of direct injection (DI) and jet ignition (JI) to produce high efficiency, high power-density, positive-ignition (PI), lean burn stratified, internal combustion engines (ICEs). Adopting this concept, the latest FIA (Fédération Internationale de l’Automobile) F1 engines, which are electrically assisted, turbocharged, directly injected, jet ignited, gasoline engines and work lean stratified in a highly boosted environment, have delivered peak power fuel conversion efficiencies well above 46%, with specific power densities more than 340 kW/liter. The concept, further evolved, is here presented for unmanned aerial vehicle (UAV) applications. Results of simulations for a new DI JI ICE with rotary valve, being super-turbocharged and having gasoline or methanol as working fuel, show the opportunity to achieve even larger power densities, up to 430 kW/liter, while delivering a near-constant torque and, consequently, a nearly linear power curve over a wide range of speeds.
Boretti, Alberto
Computational Optimization of Pressure Wave Reflection on the Piston Surface for Single Point Autoignition Gasoline Engine with Colliding Pulsed Supermulti-Jets Leading to Noiseless-High Compression and Nearly-Complete Air-Insulation2019-01-02354/2/2019
A new engine concept based on pulsed supermulti-jets colliding at a small area around the chamber center was proposed in our previous research. It was expected to provide noiseless high compression ratio and nearly-complete air-insulation on chamber walls, leading to high thermal efficiency. In the previous reports, three-dimensional computations for the unsteady compressible Navier-Stokes equation were conducted, which were qualitative because of using regular grid method. This time, we develop a new numerical code in order to quantitatively simulate the compression level caused by the jets colliding with pulse. It is achieved by applying a staggered grid method to improve conservatibity of physical quantities at very high compression in combustion phenomena. Computations at a simple condition were fairly agreed with a theoretical value. Computational results obtained for a complex geometry of an engine by the new code had less error than one with previous codes. In addition, the results led us to an idea of new disposition of nozzles to achieve higher compression ratio. Furthermore, we tried to optimize the effect of pressure wave reflection on the piston surface by changing the movement of piston in order to achieve higher compression ratio leading to lower exhaust energy.
Hosoi, Aya, Konagaya, Remi, Kawaguchi, Sota, Sogabe, Yasuhiro, Yamashita, Yuya, Naitoh, Ken
Supplemental Propulsion System Performance Station DesignationAIR6508 (Current)1/3/2019
This SAE Aerospace Information Report (AIR) supplements the AS755 performance station designation system for complex or unconventional propulsion cycles and their derivatives. The station numbering conventions presented herein are for use in all communications concerning propulsion system performance such as computer programs, data reduction, design activities, and published documents. They are intended to facilitate calculations by the program user without unduly restricting the method of calculation used by the program supplier. The contents of this document will follow AS755 and AS6502 where applicable. The list of symbols presented herein will be used for identification of input and output parameters. These symbols are not required to be used as internal parameter names within the engine subprogram.
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
PROPELLER SHAFT ENDS - FLANGED SMALL AIRCRAFT ENGINEARP502A (Current)11/28/2018
E-25 General Standards for Aerospace and Propulsion Systems
Measurement Data and Reference Values for Compounds Potentially Found in Aircraft Engine Bleed AirAIR7521 (Current)10/9/2018
This document summarizes published measurement data and reference values for marker chemical compounds listed in ARP4418 (see 2.1.1) potentially found in aircraft engine bleed air.
E-31B Bleed Air Committee
Modeling of Ducted-Fan and Motor in an Electric Aircraft and a Preliminary Integrated Design01-11-02-000710/4/2018
Electric ducted-fans with high power density are widely used in hybrid aircraft, electric aircraft, and VTOL vehicles. For the state-of-the-art electric ducted-fan, motor cooling restricts the power density increase. A motor design model based on the fan hub-to-tip ratio proposed in this article reveals that the thermal coupling effect between fan aerodynamic design and motor cooling design has great potential to increase the power density of the motor in an electric propulsion system. A smaller hub-to-tip ratio is preferred as long as the power balance and cooling balance are satisfied. Parametric study on a current 6 kW electric ducted-fan system shows that the highest motor power density could be increased by 246% based on the current technology. Finally, a preliminary design was obtained and experiments were conducted to prove the feasibility of the model.
Jin, Yuzhi, Qian, Yuping, Zhang, Yangjun, Zhuge, Weilin
Burner Rig Testing of A500® C/SiCTBMG-3302410/1/2018
There is growing interest in developing, testing, and deploying ceramic-matrix composites (CMCs) into commercial and military aerospace gas turbine engines due to their durability under extreme conditions and weight-savings potential. For military applications, the focus is on the afterburning section of the turbine engine, including the flameholder, augmentor liner, and both the convergent and divergent segments of the exhaust nozzle. These are demanding applications because of the high temperatures and rapid thermal cycles.
Impact of Engine Age and Engine Hardware on Low-Speed Pre-Ignition2018-01-16639/10/2018
Low-speed pre-ignition (LSPI) is a well-studied phenomenon in boosted, spark ignition engines. The impact of lubricant formulation has received a lot of attention in recent years, yet the impact of engine hardware and engine wear on LSPI is still not fully understood. This paper addresses some of these questions using results from multiple installations of the GM 2.0 L LHU engine platform. In the first part of the study, the effect of engine life on LSPI activity was observed, and it was found that engines were susceptible to variations in LSPI activity during the initial LSPI tests with the activity eventually reaching a “stabilized” level. It was further observed that the LSPI activity generally continued to decline at a steady rate as the engine aged. For engines used in LSPI testing, the life of the engine is often limited as LSPI activity decays with age. This reduction in LSPI activity may correlate to the engine liner wear and it is suggested that the amount of oil transport along the engine liner, which is a function of the liner roughness amongst other factors, is a dominant mechanism for this observed reduction. This observation highlights the importance of baseline testing throughout the life of the engine which is critical for severity adjustments of oils tested at different times. The effect of hardware component replacement on LSPI activity was also investigated. It was determined that the removing, cleaning, and replacing of both pistons and rings had no effect on LSPI activity and did not require re-stabilization of the test engine.
Kalaskar, Vickey B., Swarts, Andre, Alger, Terrence
Selected Aerospace Diameter Pitch Combinations of Metric 60° Screw Threads for Nuts and BoltsAS1337A (Current)8/23/2018
This Aerospace Standard establishes the preferred diameter-pitch combinations of ISO metric 60° screw threads recommended for use in the aerospace industry for metric module bolts and nuts.
E-25 General Standards for Aerospace and Propulsion Systems
Horsepower Correction FormulaeARP2C (Current)8/9/2018
This document discusses formulae considered applicable to aircraft engines having integral supercharging without aftercooling, and using gasoline introduced at the entrance to the supercharger or directly into the cylinders. Such engines are normally designated as single and two speed engines. Correction formulae for engines having two stage or exhaust turbo supercharging will not be discussed. Corrections for engines having a high degree of integral supercharging will be discussed in general terms only and no specific formulae will be presented. The correction formulae and methods listed are empirical and subject to error due to conditions beyond the scope of known corrections. Usage has indicated, however, that the correction formulae listed will provide a satisfactory approximation of power output under standard conditions.
E-25 General Standards for Aerospace and Propulsion Systems
Super-Turbocharging the Gasoline Engine2018-28-00077/9/2018
In this paper, the concept of super-turbocharging is applied, in simulation, to a four-cylinder direct injection jet ignition gasoline engine. Turbocharging improves the power density of internal combustion engines, both the compression ignition and the spark ignition. However, a standalone turbocharger suffers from transient and steady state performance and efficiency degradation where the energy to turbine is either smaller or larger than what would be needed to optimize the engine operation in a specific point. Hence a concept is proposed to use a super-turbocharger, where the turbocharger shaft is connected to the crankshaft through a continuously variable transmission (CVT) and a gears pair. Energy is drawn from the crankshaft or delivered to the crankshaft to better work in every operating point. The concept was originally proposed for a diesel engine. Here it is applied to a gasoline engine. Results of simulations of engine performance are presented and discussed, prompting a conclusion that super-turbocharging would be suitable solution for gasoline engines, in terms of energy recovery, efficiency, boosting performance at low speed, and reducing the turbo lag.
Boretti, Alberto
Definitions, Aircraft Reciprocating Engine PerformanceAS20D (Current)6/20/2018
This document lists definitions that are commonly used in describing aircraft reciprocating engine performance.
E-25 General Standards for Aerospace and Propulsion Systems
Enhanced Low-Order Model with Radiation for Total Temperature Probe Analysis and Design01-11-01-00035/16/2018
Analysis and design of total temperature probes for accurate measurements in hot, high-speed flows remains a topic of great interest in aerospace propulsion and a number of other engineering areas. One can apply detailed computational methods for simultaneous convection, conduction and radiation heat transfer, but such approaches are not suitable for rapid, routine analysis and design studies. For these studies, there is still a place for low-order approximate methods, and that is the subject of this article. Here, an enhanced, low-order model is presented that includes conduction with variable thermal conductivity, convection with varying convection coefficient, varying diameter (and thus area) along the length of the sensor and radiation, all implemented in a convenient MATLAB code. We have also developed a new novel procedure to integrate the enhanced low-order model with computational fluid dynamics/conjugate heat transfer (CHT/CFD) simulations to accurately predict the important influences of radiation under different conditions in a very efficient manner.
Vincent, Tyler, Schetz, Joseph, Lowe, K. Todd
Mount - ThermocoupleARP464 (Current)5/3/2018
E-32 Aerospace Propulsion Systems Health Management
Control Lever Connections (60° V Serrations)ARP260E (Current)4/28/2018
This SAE Aerospace Recommended Practice (ARP) provides the definition for a control lever connection with 60° "V" serrations for aircraft engine to aircraft power or control levers.
E-25 General Standards for Aerospace and Propulsion Systems
Altitude Graphs Aircraft Reciprocating Engine PerformanceAS1C (Current)4/19/2018
This SAE Aerospace Standard (AS) provides for aircraft reciprocating engines formats for altitude graph sheets recommended for use when presenting engine performance data.
E-25 General Standards for Aerospace and Propulsion Systems
Exploring the Potential of Combustion on Titan01-11-01-00024/7/2018
Significant attention has been focused on Mars due to its relative proximity and possibility of sustaining human life. However, its lack of in-situ sources of energy presents a challenge to generate needed energy on the surface. Comparatively, Titan has a nearly endless source of fuel in its atmosphere and lakes, but both are lacking in regards to their oxidizing capacity. The finding of a possible underground liquid ammonia-water lake on Titan suggests that oxygen might actually be within reach. This effort provides the first theoretical study involving a primary energy generation system on Titan using the atmosphere as a fuel and underground water as the source for the oxygen via electrolysis from wind generated electricity. Thermodynamic calculations and use of chemical kinetics in a zero-dimensional Homogeneous Charge Compression Ignition (HCCI) engine model demonstrate that is indeed possible to operate an internal combustion engine on the surface of Titan while providing heat for terraforming and human activities. Subsequent terraforming estimates illustrate that while the potential for energy and heat exists, the amount of needed hardware is largely impractical. However, the findings may stimulate further curiosity by others to look towards outer space and imagine what might be possible.
Depcik, Christopher
An Innovative Hybrid Powertrain for Small and Medium Boats2018-01-03734/3/2018
Hybridization is a mainstream technology for automobiles, and its application is rapidly expanding in other fields. Marine propulsion is one such field that could benefit from electrification of the powertrain. In particular, for boats to sail in enclosed waterways, such as harbors, channels, lagoons, a pure electric mode would be highly desirable. The main challenge to accomplish hybridization is the additional weight of the electric components, in particular the batteries. The goal of this project is to replace a conventional 4-stroke turbocharged Diesel engine with a hybrid powertrain, without any penalty in terms of weight, overall dimensions, fuel efficiency, and pollutant emissions. This can be achieved by developing a new generation of 2-Stroke Diesel engines, and coupling them to a state-of-the art electric system. For the thermal units, two alternative designs without active valve train are considered: opposed piston and loop scavenged engines. The design of the alternative engines is carried out through CFD simulations. The CFD has been calibrated and validated using experimental data from single-cylinder loop scavenged engine. The study demonstrates that the new Loop scavenged engine with a 23 kWh battery pack and an Opposed Piston design with a 15 kWh battery pack can meet the goals of the project while providing 5% and 10% fuel efficiency improvement at cruise conditions respectively, in comparison to the reference 4-stroke engine.
Mattarelli, Enrico, Rinaldini, Carlo Alberto, Savioli, Tommaso, Warey, Alok, Gopalakrishnan, Venkatesh, Potter, Michael
Thermodynamic and Practical Benefits of Waste Energy Recovery Using an Electric Turbo-Generator Under Different Boosting Methods2018-01-08514/3/2018
This paper provides insight into the tradeoffs between exhaust energy recovery and increased pumping losses from the flow restriction of the electric turbo-generator (eTG) assessed using thermodynamic principles and with a detailed GT-Power engine model. The GT-Power engine model with a positive displacement expander model was used to predict the influence of back pressure on in-cylinder residuals and combustion. The eTG is assessed for two boosting arrangements: a conventional turbocharger (TC) and an electrically assisted variable speed (EAVS) supercharger (SC). Both a low pressure (post-turbine) and high pressure (pre-turbine) eTG are considered for the turbocharged configuration. The reduction in fuel consumption (FC) possible over various drive cycles is estimated based on the steady-state efficiency of frequently visited operating points assuming all recovered energy can be reused at an engine efficiency of 30% with 10% losses in the electrical path. On the city FTP and US06 cycles, the EAVS SC engine benefits more than the turbocharged from adding the eTG. The opposite is observed for the highway cycle where adding the eTG causes greater fuel consumption reductions for the turbocharged engine. Boost reserve in the TC case at low load, however, makes the EAVS SC with eTG (boost-by-wire) a better boosting and energy recovery system overall with reductions in FC up to 1.4%, 2.4% and 4.6% relative to the TC engine over the FTP, highway and US06 cycles respectively.
Kiwan, Rani, Middleton, Robert, Stefanopoulou, Anna
Rocket LaunchersTBMG-287804/1/2018
Arnold Defense Arnold, MO (636) 296-5417
Performance Specification Anti-Seize Thread Compound, High TemperatureAMS3050 (Current)12/12/2017
This foundation specification (AMS3050) and its associated category specifications (AMS3050/1 through AMS3050/9) cover anti-seize compounds for use on threads of nuts, studs, bolts, and other mating surfaces, including those of superheated steam installations, at temperatures up to 1050 °F (566 °C). Compounds containing PTFE are limited to 600 °F/315 °C maximum. Materials for nuts, studs, bolts and other mating surfaces include, but are not limited to Steel, Nickel alloys, Stainless Steel, Silver coated materials.
AMS M Aerospace Greases Committee
Shipping Caps, Covers and PlugsARP5862 (Current)11/6/2017
The primary purpose of the shipping closure is to protect the aircraft parts or system from damage and foreign material ingress/egress (e.g., dust, dirt or other contaminants) during transport and storage. Shipping closures are not airworthy items. Therefore, their usage is defined as preventative for the parts to be protected as opposed to operational. Military and commercial customer requirements for the prevention of damage or contamination to stored parts are generally limited to the generic instructions “all openings should be sufficiently covered to prevent the entrance of dust, dirt, moisture or other foreign contaminants”. This recommended practice outlines basic minimum parameters for suggested item construction and usage. Additionally, this recommended practice provides instruction on how to apply these closures to various openings.
AGE-4 Packaging, Handling and Transportability Committee
Effect of Direct Water Injection Timing on Common Rail Diesel Engine Combustion Process and Efficiency Enhancement2017-01-228110/8/2017
The present work aims at optimizing diesel engine combustion efficiency with optimized water injection strategy. The engine had been modified based on a two-cylinder mechanical pump diesel engine into common rail diesel engine with capability of direct water injection. The direct water injection system was designed and manufactured independently. An air-fluid booster was utilized to establish the water injection pressure up to 40MPa. Customized diesel injector was selected to be used as water injector in this study. Water injection strategy was optimized in detail with injection timing around TDC which ranges from 12°CA BTDC to -5°CA BTDC under 10 bar IMEP. The engine efficiency can be improved under selected water injection strategy due to the increment of work fluid in the combustion chamber. Moreover, the nitric oxides emissions show decrement around 10%. As the water injection timing approaching TDC, the efficiency enhancement rate increased and reached its peak value at 5°CA BTDC. The enhancement rate dropped as the injection timing further postpones. The water injection timing shows little effect on the nitric oxides emissions under the selected water injection duration. It can be predicted that the enhancement rate can be improved as engine load increases.
Jiang, Lang, Kang, Zhe, Zhang, Zhehao, Wu, Zhijun, Deng, Jun, Hu, Zongjie, Li, Liguang
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